Grand Rounds

Selective IgM deficiency. It is rare with an incidence of less than 0.03 percent in the general population and 1 percent in hospitalized patients. {1} It was previously known as type V dysgammaglobulinemia. {2} It has been described as a consequence of immunosuppression but primary antibody deficiency may be inherited as autosomal recessive partly influenced by X-Chromosomal products. {3} Patients have serum IgM levels Less than 20 mg, dL to undetectable levels with normal levels of other immunoglobulins. {4} Infants with IgM deficiency tend to develop overwhelming and life-threatening infections with both encapsulated bacteria e.g., pneumococci, H. influenzae, meningococcal, pseudomonas and other gram negative bacteria. {5} Older children may have atopic dermatitis, autoimmune diseases or malignancy. {6} Patients with selective IgM deficiency are susceptible to chronic diarrhea and respiratory infections. {7} Our patient had repeated diarrhea. Growth is stunted and children are malnourished secondary to recurrent infection as was seen in our patient. The cause of selective IgM deficiency is unknown. It is hypothesized that selective IgM deficiency results from either insufficient T helper cells or increased T suppressor cell function that interferes with B cell differentiation into IgM. IgM committed number of B cells and cell mediated immunity is intact. {8} Some patients are capable of normal antibody response in other immunoglobulin classes following specific immunization, whereas others respond poorly. {9} Insufficient data is available to determine the best treatment in these patients. Antibiotics should be started for all patients with infection and prophylaxis with antibiotics should be continued. {5} Since commercially available Intravenous Immunoglobulin {IVIg} has only traces of IgM, it may not be of much use except in patients who are unable to mount adequate antibody titers to specific antigens such as tetanus or pneumococcal vaccine. Prompt treatment of infections helps to decrease mortality and morbidity, however in patients with life-threatening infections, prognosis is poor.

References :

Inoue T, Okumara Y, Shirahama M et al. Selective partial IgM deficiency : Functional assessment. Clin Immunol 1986; 6(2):130-135. Ross IN, Thompson RA. Severe selective IgM deficiency. Journ Clin Pathol 1976; 29:773-777. Hayward A. Immunodeficiency. In : Lachmann PJ, Peters DK edn. Clinical Aspects of Immunology, Vol 2, 4th Edn. Oxford : Blackwell Scientific Publications; 1982:1672-1673. Cleveland M. Antibody deficiency syndromes. Pediatr Clin North AM 2000;47:1240. Ammann AJ, Stiehm R. Antibody (B cell) Immunodeficiency Disorders. In : Daniel P Stites, Abba Terr, Trisham G Praslow eds. Medical Immunology. London : Prentice Hall International Inc ;1997:342. Ochs HD, Winkelstein J. Disorder of B-cell system In : Steihln ER eds. Immunologic Disorders in Infants and Children. 4th edn. Philadelphia. WB Saunders; 1996:296-338. Rao B. Immunoglobulin M Deficiency. Available at website http://www.emedicine.com Accessed on 18th November 2005. De la Concha EG, Garcia – Rodriguez MC, Zabay JM. Functional assessment of T and B lymphocytes and antibody deficiency. Clin Exp Immunol 1982;49:670-676. Zaka-ur-Rab Z, Gupta P. Pseudomonas septicemia in selective IgM Deficiency. Indian Pediatr 2005; 42:961-962.